Researchers have recorded brain patterns of a dying man to understand what happens at the end of life. 

A new report describes observations from continuous electroencephalography (EEG) recordings from the brain of a dying 87-year-old man experiencing a heart attack after a traumatic subdural hematoma.

EEG is used to monitor consciousness, memory, and perception activities in brains, and has been used to show that there is a recollection of memories in a conscious brain during a near-death experience (NDE).

A more recent study involved an 87-year-old male patient who presented to an emergency department after falling. His condition declined after his admission, simultaneously experiencing anisocoria, unequal pupil size, and a bilateral reaction to light.

He experienced bilateral acute subdural hematomas (SDH) and a left decompressive craniotomy was performed to remove the hematoma. 

Following this, he continued to decline due to continuous seizures identified through EEG.

The patient’s family signed a “Do-Not-Resuscitate (DNR)”, which ceased any additional treatment until he was allowed to pass away.

The EEG recordings show that during the transition to death, the human brain experiences a surge in absolute gamma power, even after the neuronal activity in both hemispheres ceases.

The researchers also observed an intricate interplay between low- and high-frequency brainwaves occurring after neuronal activity ceased, which persisted until all blood flow to the brain was cut off due to cardiac arrest.

The researchers say there are several factors that may have contributed to the observed EEG activity. A lack of oxygen may have increased cortical excitability after the patient’s injury, and it is expected that anaesthesia had an impact on neuronal oscillations too. Overall, it appears clear that the dying human brain experiences varying activity changes during the transition to death.

The full study is accessible here.